package com.guaoran.headFirst.observer.interfaces;

/**
 * @author : 孤傲然
 * @Description :
 *  可观察者接口
 * @date :2018/4/27 13:46
 */
public interface Subject {
    public void addObserver(Observer observer);
    public void removeObserver(Observer observer);
    public void notifyObservers(String message);
    public void setMessage(String message);
}


